Atherosclerotic heart disease, a major cause of mortality and morbidity in the U.S., has been shown to have its origins in childhood. Deposition of calcium occurring early in the atheromatous process, is often observed in postmortem studies of coronary arteries and the aorta. Ultrafast computed tomography (Fast-CT) provides a highly sensitive, non-invasive technique for detecting the presence and quantity of coronary artery calcification (CAC). The "risk factors" for coronary artery disease have been determined by measuring levels of potential factors in middle-and older-aged adults and determining which predict atherosclerotic cardiovascular disease, including coronary artery disease (CAD), peripheral vascular disease, and cerebrovascular disease. Adult subjects with CAC have a greater number of coronary risk factors, including higher cholesterols. In the age group of 30-39 years, 30 to 40% have radiographic evidence of coronary artery or aortic calcification. In the Muscatine Study, we have examined coronary risk factors in 2400 subjects during childhood (ages 9-11 years) and again in young adult life (ages 20 to 30 years). This population can now provide important information related to measures of childhood and young adult coronary risk factors predicting the development of the atherosclerotic process in adults in their fourth decade of life. In 800 randomly selected subjects, we will examine the relationship of known coronary risk factors measured in childhood and again in early adult life in order to examine their association with CAC. In this study we will determine if childhood coronary risk factor levels or change in levels either during childhood or from childhood to adult life predict CAC in the fourth decade of life; whether adult levels or change in levels during young adult life or coronary risk factors, including lipids, lipoproteins, apolipoproteins, lipoprotein(a), apo(a) genotypes, homocyst(e)ine, and left ventricular mass, are associated with CAC; and whether the incidence and progression of CAC during the fourth decade is related to previous levels of coronary risk factors. This study will provide information linking coronary risk factor levels in children and young adults to the noninvasive assessment of the early development of the atherosclerotic process. It has the potential of identifying which coronary risk factors in childhood and young adult life are associated with the incidence and progression of atherosclerosis, identified by calcium deposition.